Abdominal closure and complications

Comparison of incisional bursting strength of a bidirectional absorbable knotless suture material versus a standard continuous absorbable suture material for closure of the equine linea alba

OBJECTIVE

To evaluate the use of bidirectional knotless barbed suture material for closure of the equine linea alba.

STUDY DESIGN

Laboratory study.

ANIMAL OR SAMPLE POPULATION

Adult light horse cadavers (n = 24).

METHODS

A 25 cm incision was made through the linea alba, and a 200 L polyurethane bladder was positioned within the abdomen. The linea alba was closed either using USP2/EP5 bidirectional polydioxanone barbed suture or USP2/EP5 standard polydioxanone suture in a simple continuous pattern. Closure time was recorded for each suture type. The bladder was air-insufflated at 40 L/min, and the pressure at body wall failure recorded. The length of suture used for wound closure and wound failure modes were recorded. Suture length, closure time, bursting pressure, and failure modes were compared using Welch-Aspin t-tests.

RESULTS

The incisional bursting pressure was comparable between the two groups (p > .05). Less suture material (p < .01) was required with the barbed suture than the standard suture. Closure time was less for the barbed suture than the standard suture (p < .01). Suture failure was the main failure mode in both groups (83% cases).

CONCLUSIONS

Closure of the equine linea alba using bidirectional barbed suture material reduced the amount of foreign material in the wound and decreased closure time without compromising incisional strength.

CLINICAL RELEVANCE

Bidirectional barbed suture material could be considered as an alternative to standard suture materials for closure of the equine line alba.

A multicenter retrospective case-cohort study on the prevalence of incisional morbidities in late pregnant mares following exploratory celiotomy (2014-2019): 579 cases

OBJECTIVE

To report the prevalence and risk factors for incisional morbidities in late pregnant and nonpregnant/early pregnant control mares following colic surgery.

DESIGN

Multicenter, retrospective, cohort study from January 2014 to December 2019.

SETTING

Two university teaching hospitals and 1 private referral center.

ANIMALS

Five hundred and seventy-nine fillies and mares ≥2 years old that underwent celiotomy. Pregnant mares (n = 54) were >240 days in gestation from the last known breeding date and were compared to control females (n = 525) undergoing colic surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Morbidity rates were not different between mare groups with 56% of pregnant mares and 51% of control mares reporting at least 1 morbidity. Incisional swelling was the most common reported complication in both groups. Incisional swelling was associated with shorter hospital stays (odds ratio [OR], 0.18; P < 0.01), and drainage was associated with a longer hospital stay (OR, 1.27; P ≤ 0.01) and with use of an abdominal bandage (OR, 4.4; P < 0.01). Herniation was associated with hypercapnia under anesthesia (OR, 1.1; P = 0.048), previous abdominal surgery (OR, 8.3; P = 0.003), and with use of an abdominal bandage (OR, 56; P = 0.006). Body wall dehiscence was associated with longer hospital stay (OR, 1.2; P < 0.01). Nonsurvival was higher in pregnant mares (13%) compared to control mares (5%; P = 0.02).

CONCLUSIONS

The prevalence of incisional morbidities did not differ between pregnant and control mares undergoing colic surgery. Several factors were associated with incisional morbidities, including the duration of surgery and anesthesia, anesthetic variables, abdominal bandage use, previous ventral abdominal incision, and longer duration of hospitalization.

Comparison of the zip skin closure system with conventional suture for skin closure of ventral midline incisions in horses

OBJECTIVE

To compare the application and healing of the zip skin closure system (ZSCS) with sutured closure by use of a split-scar model of ventral midline incisions in horses in a prospective, randomized experimental study.

ANIMALS

8 adult horses.

PROCEDURES

All horses underwent an exploratory ventral midline celiotomy with a standardized 30-cm skin incision. Each horse was randomized to have either the cranial 15 cm closed with suture and caudal 15 cm with the ZSCS or vice versa (split-scar model). Skin closure time was recorded and compared. Photography and skin biopsies were taken preoperatively and 14 days postoperatively. Cosmetic appearance was assessed by use of a proposed equine celiotomy incision score. Healing at 14 days was assessed by histopathology.

RESULTS

Skin closure times were faster with the ZSCS compared to sutured incisions. At 14 days postoperatively, the cosmetic appearance (equine celiotomy incision scores) for ZSCS incisions were better than sutured closure and histologic healing scores were not different between methods of closure. Subcuticular sutures were associated with deep dermal inflammation and necrosis independent of epidermal closure methods.

CLINICAL RELEVANCE

While limitations to the utility of the ZSCS are recognized, the potential benefits of expedient closure, good cosmetic outcome, and satisfactory healing make this method viable for closure of linear wounds or incisions in horses.

Standing flank laparotomy for colic: 37 cases

BACKGROUND

Standing flank laparotomy can be an alternative to ventral midline laparotomy in horses with colic. Standing flank laparotomy avoids general anaesthesia, provides excellent access to some regions of the abdominopelvic cavity and costs less than ventral midline laparotomy.

OBJECTIVE

To report a series of cases of peritoneal and intestinal diseases other than SC diseases managed with standing flank laparotomy.

STUDY DESIGN

Retrospective case series.

METHODS

Records from equids with colic subjected to standing flank laparotomy at five hospitals (2003-2020) were reviewed. Descriptive data analysis was performed.

RESULTS

Thirty horses (sixteen survived to discharge), six ponies (four survived) and one donkey (euthanised) were subjected to standing flank laparotomy via the left flank (n = 31), right flank (n = 2) or both flanks (n = 4). The primary disease affected the peritoneum (0/5 survived), SI (5/9 survived) and caecum and/or LC (15/23 survived). Enterotomy was performed in four animals (all survived). Partial typhlectomy was performed in one horse (euthanised). Resection-anastomosis of the SI or LC was performed in three animals (one survived). Three animals had intraoperative complications that negatively affected the outcome: Two ponies had intolerance to abdominopelvic exploration; one mare had spontaneous exteriorisation of a long segment of the SI leading to a large tear in the mesentery. In seven cases, severe/extensive lesions found during standing flank laparotomy warranted immediate euthanasia. The survival rate was 54%. All owners were satisfied with the decision to perform standing flank laparotomy.

MAIN LIMITATIONS

The retrospective design, lack of a control group, small number of cases and lack of standardised protocols between hospitals.

CONCLUSIONS

Although ventral midline laparotomy is the standard of care for horses with colic, standing flank laparotomy is a viable approach for some types of colic. Systemic administration of analgesics may not produce sufficient peritoneal analgesia, which can lead to intolerance to abdominopelvic exploration during standing flank laparotomy in horses with colic and may negatively affect the outcome.

In vitro evaluation of the modified forwarder knot used to end a continuous suture pattern in large-gauge suture

OBJECTIVE

To evaluate the strength and size of forwarder end (FE) knots modified to end continuous suture lines compared with Aberdeen (AB), square (SQ), and surgeon's (SU) knots.

STUDY DESIGN

In vitro mechanical study.

STUDY POPULATION

Knotted suture.

METHODS

Knots were tied with 2 USP (United States Pharmacopeia) polydioxanone, 2 USP, and 3 USP polyglactin 910 and tested on a universal testing machine under linear tension. Mode of failure and knot holding capacity (KHC) were recorded, and relative knot security (RKS) was calculated. Knot volume and weight were determined by digital micrometer and balance. Knot holding capacity, RKS, size, and weight between knot type, number of throws, and suture type and size were compared by using analysis of variance testing, with P < .05 considered significant.

RESULTS

In all suture types and number of throws, FE knot KHC/RKS was 28% to 66.99% (1.2-1.6 fold) stronger compared with SQ/SU knots (P < .001). For 2 USP polydioxanone, FE knots had 10% (1.1 fold) higher KHC/RKS compared with AB knots (P < .042). However, in 2 and 3 USP polyglactin 910, FE knot KHC/RKS values were not different from those of AB knots (P > .080). Forwarder end/AB knots failed by suture breakage at the knot, whereas some SQ/SU knots unraveled. Forwarder end knots in 2 and 3 USP polyglactin 910 were 21.1% to 44.4% (1.2-1.4 fold) smaller compared with SQ/SU knots (P < .028). Forwarder end knots in 2 and 3 USP polyglactin 910 were 40% to 99% (1.4-2.0 fold) larger compared with AB knots (P < .001).

CONCLUSION

Forwarder end knots provided increased KHC/RKS compared with SQ/SU knots.

CLINICAL RELEVANCE

Forwarder end knots should be considered for closures when suture is placed under tension.

Complications associated with closure of the linea alba using a combination of interrupted vertical mattress and simple interrupted sutures in equine laparotomies

OBJECTIVES

(1) Evaluate the occurrence and variables associated with incisional morbidities (IMs) after ventral median laparotomy when using interrupted vertical mattress sutures (IVMS) and (2) determine the occurrence of abdominal bandage-associated complications in horses.

METHODS

Occurrence of IM and bandage-associated complications were determined after single laparotomies (SL group; n=546 horses) and repeat laparotomies (RL group: multiple laparotomies within four weeks; n=30 horses) in horses that survived ≥7 days postoperatively. Univariate analysis and multivariate logistic regression were performed to evaluate variables associated with IM.

RESULTS

The IM rate was 9.52 per cent in the SL group and 33.33 per cent in the RL group. The actual infection rate was 5.31 per cent in the SL group and 26.67 per cent in the RL group. Overall, long-term clinically relevant wound complications was 1.68 per cent. After multivariate analysis, increased anaesthesia duration was associated with IM and performing an enterotomy and postoperative intravenous lidocaine administration were associated with incisional infection in the SL group; no parameter remained significant in the RL group. Bandage-related complications were recorded in 2.95 per cent of the cases.

CONCLUSIONS

These results suggest that the use of IVMS for closure of the linea alba is another viable option for closure and that an abdominal bandage does not appear to cause significant complications.

Incisional infections associated with ventral midline celiotomy in horses

OBJECTIVE

To review the veterinary literature regarding healing and complications associated with equine celiotomy including anatomy and physiology, risk factors for incisional infection and hernia, and treatment.

ETIOLOGY

Celiotomy is the most common approach to treat horses with surgical colic. Incision through the linea alba provides exposure to most of the abdomen for exploration, exteriorization, and correction of surgical lesions. Incisional apposition relies on suture strength during anesthetic recovery and for the first 30 days postoperatively. Factors associated with the patient, surgical lesion and procedures, anesthesia, and recovery put the horse at risk for surgical site infection. Infection is the most important risk factor for incisional hernia formation.

DIAGNOSIS

A presumptive diagnosis of surgical site infection is made based on the presence of fever and incisional swelling, pain, and discharge. Ultrasonography can be used to identify areas of fluid accumulation prior to the appearance of incisional drainage. Definitive diagnosis is based on positive bacteriologic culture of the incisional discharge. Incisional hernia is diagnosed by palpation of the incision, usually 30-60 days after surgery. Ultrasound of the incision may aide in early diagnosis of incisional hernia if gaps along the incision in the linea alba are apparent.

THERAPY

No objective data exist to assess the efficacy of specific therapies for surgical site infections following celiotomy. Principles of treatment include the establishment of drainage, bandaging, antimicrobial therapy based on culture and sensitivity, and extended rest in an attempt to avoid incisional hernia or dehiscence. Treatment for incisional hernia includes prolonged circumferential bandaging, open or minimally invasive hernia repair, or no treatment.

PROGNOSIS

Incisional complications are associated with prolonged convalescence and diminished prognosis for return to athleticism. Limiting risk factors for surgical site infections, prompt treatment, and incisional support may optimize celiotomy healing and timely return to function. Horses compete in many disciplines with incisional hernias.

Correlation Between Peritonitis and Incisional Infections in Horses

Surgical site infection of abdominal incisions is an important complication after laparotomy with increased risk of incisional hernia formation in horses. This study aims to evaluate the healing process of abdominal incisions and correlate peritonitis with the occurrence of surgical site infection and incisional hernias. Nine horses underwent standardized laparotomy, intestinal exploration, and induced septic peritonitis. Standardized relaparotomy was performed two (n = 3), four (n = 3), and six (n = 3) months later to evaluate the abdominal cavity for adhesions and to collect the sutured ventral abdominal wall to evaluate and prepare it for histopathological and tensile strength study. All horses presented with endotoxemia, controllable peritonitis, heat and touch-sensitive ventral abdominal edema and surgical wound infection with presence of purulent discharge. Adhesion of the cecum or colon to the internal portion of the surgical wound was observed. Healing of the infected surgical wounds occurred by second intention and a space between the rectus abdominis muscles developed because of the presence of a scar, which was related to incisional hernia. In the histopathological evaluation, the collagen content increased, and the inflammation decreased over time. The tensile strength increased over time and was highest after 6 months. After the second surgical intervention, there was no infection of the surgical wound in any of the animals and healing by first intention occurred. Surgical site infection may be a symptom of peritonitis in horses recovering from abdominal surgery. Infected surgical wounds heal by second intention, which favors the spacing of rectus abdominis muscle and the formation of incisional hernia.

In vitro evaluation of the knot-holding capacity and security, weight, and volume of forwarder knots tied with size-3 polyglactin 910 suture exposed to air, balanced electrolyte solution, or equine abdominal fat

OBJECTIVE

To evaluate the effect of exposure to a balanced electrolyte solution (BES), or equine abdominal fat on the knot-holding capacity (KHC), relative knot security (RKS), weight, and volume of forwarder knots versus surgeon's knots.

SAMPLE

315 knots tied and tested in vitro.

PROCEDURES

United States Pharmacopeia size-3 polyglactin 910 suture exposed to air (dry [control]), equine abdominal fat (fat-exposed), or BES (BES-exposed) was used to tie forwarder knots with 2, 3, and 4 throws and surgeon's knots with 5, 6, 7, and 8 throws. A universal materials testing machine was used to test the tensile strength of suture and knots to failure, and the KHC, RKS, weight, and volume of knots were determined.

RESULTS

Forwarder knots had significantly higher KHC and RKS and lower volume, compared with surgeons' knots. Forwarder knots tied with fat-exposed suture had greater weight, but not volume, than did forwarder knots tied with dry or BES-exposed suture with the same number of throws.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that forwarder knots were superior to surgeon's knots when configured as start knots intended for continuous lines of suture. Exposure to media did not negatively affect mechanical or physical properties of forwarder knots and may improve specific biomechanical functions, including KHC and RKS.

Early herniorrhaphy of large traumatic abdominal wounds in horses and mules

REASONS FOR PERFORMING STUDY

Surgical treatment of traumatic abdominal hernias is usually delayed for 2-3 months following injury. The residual defects are then repaired by herniorrhaphy or mesh herniorrhaphy.

OBJECTIVE

To describe the outcome following herniorrhaphy (without a mesh) within 21 days of initial injury to repair external traumatic lateral abdominal hernias in horses and mules.

STUDY DESIGN

Descriptive case series.

METHODS

Twenty-two cases were included. Surgical treatment involved exposure of the hernia sac and closing of the abdominal wall defect with interrupted Mayo mattress or cruciate sutures after reduction of the herniated organ into the peritoneal cavity. Data collected included cause and site of the hernia, surgical findings, immediate and long-term post operative complications, return to use, duration of convalescence and hernia recurrence.

RESULTS

Falling while crossing impassable pathways was the most common initial cause of the hernia (9/11 horses and 10/11 mules). Adhesion formation to underlying viscera was found intraoperatively in 2 cases. Uncomplicated healing occurred in all animals except 3 with suture abscesses and one with a subcutaneous seroma. At the time of follow-up (6-24 months after surgery), complete recovery without recurrence of herniation was achieved and animals had returned to their previous use.

CONCLUSION

Herniorrhaphy within 21 days using interrupted Mayo mattress or cruciate pattern sutures can be effective for treating external traumatic abdominal hernias in horses and mules. The Summary is available in Chinese - see Supporting Information.

Comparison of primary closure of incisional hernias in horses with and without the use of prosthetic mesh support

REASONS FOR PERFORMING STUDY

Repair of incisional hernias in horses has been described previously; however, this report describes the outcome of primary closure of incisional hernias in a large number of horses and compares these results with those of mesh implantation.

OBJECTIVE

To report the perioperative care, complications and long-term outcome of primary closure of incisional hernias in horses and to compare these results with a second population of horses in which prosthetic mesh was used.

METHODS

Medical records of horses undergoing an incisional herniorrhaphy between 1998 and 2009 were reviewed. Information obtained included case details, factors from the initial surgery that contributed to the hernia formation, method of hernia repair and outcome. Comparisons between horses with and without mesh were made using logistic regression.

RESULTS

Thirty-eight horses with primary closure and 9 horses with mesh implantation met inclusion criteria. Long-term follow-up for cases in which a mesh was not used was available for 25 cases; of these, 21 horses (84%) had a normal cosmetic appearance and 4 (16%) had a visible defect. There was no significant difference between the 2 repair methods in terms of age, sex, breed, weight, size of the hernia, number of defects, timing of the repair or cosmetic outcome. Horses in which a mesh was used had significantly longer duration of surgery and hospitalisation, and were significantly more likely to develop post operative complications while having a longer duration of convalescence prior to return to use.

CONCLUSIONS

Primary apposition of incisional hernias in horses without the use of mesh support appears to result in a good cosmetic outcome while avoiding the complications associated with mesh implantation in this population of horses.

POTENTIAL RELEVANCE

Surgical time, duration of hospitalisation, and post operative complications may be reduced by using this technique of primary repair and avoiding mesh implantation.

T-shaped malformation of the ventral colon in a Thoroughbred filly with colic

A 4-month-old Thoroughbred filly presented for abdominal pain was diagnosed with a T-shaped malformation of the ventral colon at exploratory laparotomy. Following resection and anastomosis of the large colon, no further episodes of abdominal pain occurred during a 12-month follow-up. Acute dehiscence of the linea alba occurred as a complication of the initial laparotomy, but was successfully managed following additional surgical repair. T-shaped malformation of the ventral colon has not previously been reported and is considered a congenital malformation of mesocolon formation.

Survival and complication rates in 300 horses undergoing surgical treatment of colic. Part 4: Early (acute) relaparotomy

REASONS FOR PERFORMING STUDY

Early (acute) relaparotomy after surgery for equine colic is widely considered to be an acceptable treatment option for management of certain post operative complications. However, there is relatively little published information about resulting complication rates and short- and long-term outcomes.

OBJECTIVES

To document the proportions, indications, complication rates and survival rates of horses undergoing acute relaparatomy following colic surgery.

METHODS

History, clinical findings, surgical findings and procedures, post operative treatments and outcome of 300 consecutive surgical colic cases (1994-2001) were reviewed. Long-term follow-up information was retrieved from case records and telephone enquiries from owners.

RESULTS

Acute relaparotomy was performed in 27/254 horses (10.6%) that recovered from initial general anaesthesia. The indications for relaparotomy included persistent pain, persistent ileus, peritonitis and wound breakdown. Of these 27 horses, 21 (77.8%) recovered from the second surgery, of which 8 (29.6%) died during the immediate post operative period. Thirteen of the 27 horses (48.2%) were discharged. Of these 13 horses, 5 (38.5%) were re-admitted to the hospital for surgical treatment of a subsequent bout of colic. The long-term survival rate for the 27 horses that underwent relaparotomy was 22.2%. Colic following discharge after relaparotomy was recorded in 69.2% of cases.

CONCLUSIONS

Relaparotomy is necessary in approximately 10% of horses undergoing surgery for acute colic. Persistent pain and post operative ileus were the most common indications. The short-term survival rate for horses requiring relaparotomy was approximately 50% and the long-term survival rate 22%. Nearly 40% of horses surviving relaparotomy developed episodes of acute colic that necessitated further surgery.

POTENTIAL RELEVANCE

Owners of horses requiring early (acute) relaparotomy should be advised of the high complication rates for this procedure.

Update on recent advances in equine abdominal surgery

In recent years important advancements in colic surgery have led to improved prediction of survival rates, better survival rates, and decreased complication rates. This article describes several modalities to combat and prevent incisional hernia and intestinal adhesion formation in horses undergoing colic surgery. These modalities have had a positive impact on reducing complications in horses after surgery.